秸秆两步发酵法制备丁二酸研究

目的：以秸秆为原料进行生物转化制备有机酸。方法：在秸秆汽爆法预处理的基础上，以绿色木霉为菌种进行秸秆降解发酵，对降解单糖接种放线杆菌进行二次发酵制备丁二酸。结果：第一步绿色木霉发酵时，通气量0.3L/L·min，30℃发酵36h，后将发酵扩增8倍进行55℃酶解24h，五、六碳糖累积浓度达到49.4g/L。第二步产丁二酸放线杆菌发酵时，控制温度37℃、罐内CO2 压力0.11MPa、转速250r/min，发酵40h，最终产丁二酸累积浓度为67g/L。结论：秸秆制备丁二酸的两步发酵法工艺具有工业推广价值。

Preparation of Succinic Acid from Crop Straw via Two-step Fermentation

Objective: To produce a large scale of succinic acid through the bioconversion of crop straw. Methods: Crop straw was pretreated by steam-explosion method. Then Trichoderma viride was used to degradating crop straw in the first-step fermentation and Actinobaccillus succinogenes was used for producing succinic acid in the second-step fermentation. Results: The yield of pentose and hexose is about 49.4 g/L when the conditions of first-step fermentation were as follows: fermentation at 30 ℃ for 36 h, then enlargement of the broth by 8 times of volume and hydrolysis at 55 ℃ for 24 h. The yield of succinic acid is about 67 g/L when the second-step fermentation condition was as follows: jar pressure of CO2 0.11 MPa, rotation rate 250 r/min, and fermentation at 37 ℃ for 40 h. Conclusions: The two-step fermentation technology is worth extending to industrial production of succinic acid from crop straw.